This invention relates, generally, to an optical reader head and a method and circuit for providing video compensation, and in particular, it relates to such a reader head, method, and circuit which are useful in a high speed document reading application.
One of the problems associated with a typical prior art optical reader is that it requires a high intensity of light to illuminate a document positioned at a scanning line associated with the reader. Generally, the high intensity light is located away from the scanning line, and it is delivered to the scanning line by a plurality of light pipes. If the high intensity lamp were positioned next to the document at the scanning line, there is a remote possibility that the high heat from the lamp might damage or burn the document whenever a document jam occurred at the scanning line.
Another problem associated with a typical prior art reader is that it is difficult to keep the optics in the reader in alignment. When adjustments are necessary, it is difficult and time consuming to make the adjustments.